Spatial constraint drives negative frequency dependent selection of phage weaponization

Bacteria often produce and live within biofilm communities in natural environments, where they also encounter many threats including bacteriophages. Here we show how temperate phages can alter the fitness of their host via lytic induction and phage release within biofilms of <i>V. cholerae</i> on lab-grown marine snow particles. Using a combination of modeling and imaging experiments, we document that the spatial constraints of biofilm architecture and phage-neutralizing superinfection immunity place limits on the extent to which lysogens can competitively displace non-lysogens via phage release.